Help in selecting software please.

I have an RB20 mill which I have fitted steppers to. Today I have
ordered a couple of Gecko stepper drivers. Now I have to make the
biggest decision, what software. So far I have found Mach2 and
Kellycam. The pc I have may limit things as its only a p100 with 32
RAM. I dont really want to have a better pc in my garage than my
house, but if there is an overwhelming reason to get one package over
another I can bend on that.
I am more interested in engineering than engraving .
I tried looking back through some of the posts here but as there are
about 70,000 my eyes glazed ever after reading about 100.

I would appreciate any help on where to steer

Mike